Playing music to speaker...

I haven't got a Sonos yet but I am considering one. Right now it's between the Play 3 and the Bose Soundwave II. Anyway, I had a quick question:

Once I had the Sonos speaker set up, is it just a matter of going into my itunes and hitting play on a song or onto an Internet radio app (say, TuneIn) and clicking on a station, or do you have to use the Sonos app to work through?

Also, right now the Sonos Play 3 is not portable (that I'm aware of) in that it cannot run off battery power. Is there any talk of such a player coming around anytime soon?

Thanks for any help!